Thurmond Lake hit its highest level in five years Thursday, prompting the Army Corps of Engineers to begin releasing excess water in flood-control mode.
Although the reservoir has been affected by severe drought for three years - and was 14 feet low in November - recent rains elevated the pool to 332 feet above sea level.
"Full pool is 330, but this time of year we expect it to be 328, so we're 4 feet into flood control right now," said Corps spokesman Jim Parker. The lower March pool is designed to provide capacity for spring rains.
The last time the lake had as much water was May 11, 1998, when the reservoir swelled to a near-record 333.94 feet, prompting accelerated releases through the dam into the Savannah River.
On Thursday, the Corps again went into flood-control mode, and releases through the dam were bumped up to 21,000 cubic feet per second in efforts to lower the lake to provide additional storage.
During the drought-management mode, under which the dam has been run for three years, releases had been held to a minimum - usually averaging 3,600 cubic feet per second.
If the lake continues to rise, which is unlikely, the Corps can open its floodgates to prevent water from topping the dam. The usual method is to release water through the dam's turbines, which generate electricity.
Although the river has swollen somewhat, the volume of water being released doesn't create flooding hazards downstream.
"But obviously with this much flow, there will be more water in the river, and people need to be aware of that, and also watch for more debris," Mr. Parker said.
Flows of 25,000 cubic feet per second can begin to cause complaints.
Rainfall has pumped 2.34 inches into the Thurmond Lake drainage basin this month, compared with 1.17 inches at Lake Hartwell.
Lake Russell, which lies between the reservoirs, received about 1.78 inches of rainfall this month.
Reach Robert Pavey at (706) 868-1222, Ext. 119, or firstname.lastname@example.org.